Abstract:

Flying unmanned aerial vehicles can be easily affected by such uncertain factors as disturbance andunmodeled dynamics.In order to solve this problem,a new robust flight control law design method is proposed.Based on the framework of a baseline controller and an augmented compensator,the baseline controller uses arobust servomechanism LQR control method so as to provide the basic command to track the control input.Then,by using the ideal closed loop system of the baseline controller as a reference model,the augmented compensator onthe basis of robust model- reference adaptive control algorithm is constructed,so that the adverse effect caused bybounded disturbance and unmodeled dynamics is reduced.Theoretical analysis demonstrates that the proposedcontrol law is able to ensure the closed- loop system of being stable and the output tracking error of being bounded inthe presence of bounded disturbance and unmodeled dynamics.The comparative nonlinear simulation resultsdemonstrate that the proposed control system is able to reject various kinds of disturbances,indicating that the pro-posed system is effective and robust.

Key words: Unmanned Aerial Vehicle, Flight control, Robust Servomechanism LQR, Robust Model reference control